Conventionally, in a battle game server, each user's deck is formed by a plurality of battle cards or the like stored for each user, and the battle game server allows a plurality of users to compete with each other based on the total value of the attack strength and defense strength of the deck (for example, see JP 2008-220984 A (PTL 1)). In such a battle game server, the user acquires a battle card by methods such as purchasing the battle card.
In a conventional battle game server, however, the methods for acquiring battle cards and the like are limited, causing the user to lose interest in the game. In particular, since it is difficult to acquire a battle card or the like with a high rarity value, the user ends up with the impression that such an item cannot be acquired at all and suffers a drastic loss of interest in the game.
Exemplary embodiments of present disclosure have been conceived in light of the above circumstances and therefore provides a server, a method of controlling a server, and a program that can increase the variations on methods for acquiring a battle card or the like and enhance interest in the game.